Re: [PATCH] serial: core: fix broken console after suspend

From: Ilpo Järvinen
Date: Wed Mar 01 2023 - 06:33:19 EST


On Wed, 1 Mar 2023, Lukasz Majczak wrote:

> Re-enable the console device after suspending, causes its cflags,

Re-enabling

> ispeed and ospeed to be set anew, basing on the values stored in
> uport->cons. The issue is that these values are set only once,
> when parsing console parameters after boot (see uart_set_options()),

Remove "The issue is that" from here and just state:

"These values are set only once when parsing console parameters after boot
(see uart_set_options())."

> next after configuring a port in uart_port_startup() these parameteres

parameters

> (cflags, ispeed and ospeed) are copied to termios structure and
> the orginal one (stored in uport->cons) are cleared, but there is no place

original

> in code where those fields are checked against 0.
> When kernel calls uart_resume_port() and setups console, it copies cflags,
> ispeed and ospeed values from uart->cons,but those are alread cleared.

missing space after comma.

alread -> already

> The efect is that console is broken.

effect

> This patch address this by preserving the cflags, ispeed and

Too many "this", don't start with "This patch" but go directly to the
point.


--
i.


> ospeed fields in uart->cons during uart_port_startup().
>
> Signed-off-by: Lukasz Majczak <lma@xxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
> drivers/tty/serial/serial_core.c | 3 ---
> 1 file changed, 3 deletions(-)
>
> diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
> index 2bd32c8ece39..394a05c09d87 100644
> --- a/drivers/tty/serial/serial_core.c
> +++ b/drivers/tty/serial/serial_core.c
> @@ -225,9 +225,6 @@ static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
> tty->termios.c_cflag = uport->cons->cflag;
> tty->termios.c_ispeed = uport->cons->ispeed;
> tty->termios.c_ospeed = uport->cons->ospeed;
> - uport->cons->cflag = 0;
> - uport->cons->ispeed = 0;
> - uport->cons->ospeed = 0;
> }
> /*
> * Initialise the hardware port settings.
>